decent sleight, but you forgot your angles at the last second of the video, like ronchi said, the switched out pieces are visible. if your seated, just lap the paper with your turn over motion and bam, no trace.

Caution now, this is a classic sleight-of-hand magic trick, which dave has done himself. It could do with an explanation as to how it's performed (I think we're invited to go through it carefully and spot it), but it doesn't warrant caps.